MBP disconnects IPhone everytime saying the USB is drawing too much power?

Hi Guys,

Today I went and bought myself a new Mac Book Pro 13".

Tonight I've been transfering all my files over from my old MacBook and everytime I try to connect my IPhone 3GS by USB to my Mac a message comes up straight away saying "A device conected to your computer is drawing too much power, apple has disconected this device to prevent damage occuring to your computer"

I have tried to connect my phone numerous times while it has been conected to the power cord and also running on battery.

It also took my new Mac a good half an hour to recognise my external hard drive was connected and let me use it..

I have had this problem once or twice with the same IPhone and my old mac so im thinking it may be a problem with my phone considering it is 2 years old now?

But then again, my old mac that is nearly 4 can still connect to my phone when my new MBP can't.

Any help would be appreciated.

Thanks,